The invention is directed to a coding mechanism for assemblies pluggable into a backplane wiring. The backplane wiring is composed of a wiring backplane having contact blades introduced thereinto, and of blade connectors pluggable thereonto. A rectangular housing open at one side is provided for the acceptance of spring clips which are firmly joined to electrical assemblies. Both the blade connectors as well as the spring clips are composed of individual sub-strips whose lengths correspond to a single or multiple of the length of a given sub-segment.
Such backplane wirings are disclosed, for example, by German Utility Model 9509375, incorporated herein. Their advantage is that a single embodiment suffices for all demands possibly deriving, given a wiring backplane occupied by pins arranged in grid-like fashion.
Traditional coding mechanisms are not suitable for such backplane wirings since one part of the coding mechanism must be arranged next to the blade connector and, thus, an optimum equipping of the wiring backplane with assemblies can no longer be realized. A traditional coding mechanism of this type for a plug connection composed of blade connectors and spring clips is disclosed, for example, by German Utility Model 8428427, incorporated herein. An optimum equipped with additional, special contacts. In these cases, a modular arrangement, and thus an arbitrary arrangement within the plug, is not possible.